Rotary drill bit



Patented Mar. .16, 1926.

UNITED STAT recon s. now, or LOS enemas, cannon.

rarev I. EIGHENHOFEB, GE L08 Application filed June 7,

To all whom it may concern:

Be it known that I, JACOB S. BROWN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Rotary Drill Bits, of which the following is a specification.

My invention relates to rotary bits for well drilling ap aratus of that character having ducts to a low the circulation of relatively thin mud from the drill pipe to the blades of the bit. In bits of this character two or more ducts are provided, and these ducts are of uniform diameter and disposed in parallelism with each other. It has been found that bits of this character are unsuccessful because after relatively short use the ducts become clogged with particles of mud thus discontinuing the circulation of the liquid or mud to the bit blades, and with the ultimate destruction of the blades.

It is a pm ose of my invention to provide a rotary it having ducts whlch are so shaped and arranged one with respect to the other, to reclude the possibility of them becoming clbgged and to thus insure the positive circulation of liquid to the bit blades.

It is also a purpose of my invention to provide a bit having shields arranged to relieve thev ressure of liquid at the discharge ends of t e ducts and to direct the liquid into intimate relation with respect to the cutting edges of the blades.

Although I have herein shown and described only one form of rotary bit embodying my invention, it is to be understood that various changesand modifications may be made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

In the accompanying drawings Fi 1 isa view showing a side elevation of one form of bit embodying my invention. o r

"* Figure 2 is a vertical sectional view-taken on the line 2-2 of Fig. 1. i

Fig. 3 is a transverse sectional view taken on the line 3-3 of Fig. 1.

Referrin specifically to the drawings in which siar reference characters renter to similar parts, my invention, in its present embodiment, com rises a substantla ly flat body 15 of suita 1e width, thickness, and length, having its upper end formed with a 51. serial Ho. M929.

' head includingv an annular shoulder 16 (1 a connecting nipple .17, the latter being threaded to provide a connection between the int and a drill pipe. The lower end of the body 15 is formed with fishtail blades 18 and 19 having their cutting edges re- 69 versely disposed and ofi'set in the usual manner.

As clearly shown in Fig. 2, the shoulder 16 and the nipple 17 are formed integral, and ducts 20 an 21 are formed in these elements which increase in diameter from the upper ends to the lower ends so that their longitudinal axes are disposed in converging relation to each other. The lower ends of the ducts are in direct communication wlth longitudinally extending grooves 22 and 23 which, as clearly shown in Fig. 3, are of semi-circular form and in efiect constitute a continuation of the ducts. As shown in Fig. 2, the grooves gradually decrease in depth from-their upper ends to their lower ends, and their lower ends terminate at a point above the blades 18 and 19 and in vertical alignment with the meeting ends of the blades.

As shownin Figs. 1 and 3, shields are arranged at opposite sides of the body 15, and each shiel includes a fiat portion 24 through which extends a bolt 25 for securmg the shields as a unit to the body, and a curved portion 26 arranged to partly overlie the corresponding oove 25 or 23. It "will be noted that the s ield' for one groove is disposed in reverse relation with respect to the shield of the other oove so that when the bit is rotated in t c direction of the arrow in Fig. 3, the shields serve to protect the grooves.

In practice, the bit is connected to the lower end of the drill pipe through the medium of the nip le 17 so that when mud is sup lied to the rill pipe, itwill be conducts to the blades of the bit through the ducts 20 and 21; As the liquid leaves the lower ends of the ducts, it enters the grooves 22 and 23, and under the protection of the shields is directed downwardl into intimate relation with respect to t e blades 18 and 19. The arrangement of the shields is such that dnrin rotation of the bit, the

ossibility oi roc or other solid matter bemg deposited within the grooves 22 and 23.

is positively prevented so that in. conjuncducts tiorr. With the tapering grooves, the circidotiori of liquid to the hit Modes is, et dtt times insured,

to ectuei practice, should sotid particle of mod enter either duct Q0 or 21 the force of liquid shore mud Witt serve to eject the perticle from the duct because of the increesing diameter of the duct. Itt Wilt thus be seen that any Jarticie of solid met tel which is capable 0t entering the duct is also capable being ejected therefrom thus "oreventirig chugging" ot the duet.

not It is:

it. dril't hi herring liquid conveying therein iocredsirig; it. cross sectiohzd ores trom their upper ends to their lower grooves eomrnoniceting; et their upper ends with the lower ends ot the ducts, end ehieids etteched etong corresponding, sides ot the grooves and open at the opposite sides end. errenged is overlying rotation to the grooves.

it rotary "hit comprising: at retotirefy termed in opposite sides of the hod y oedcoestitutmg e contmuotion of semi. ducts,

seid grooves decreasing in depth trorn their upper ends to their lower ends, end shields secured to the body and in portly overlying reietion with respect to the grooves for the purpose described.

3. drill bit having iiqoid conveying ducts through the heard end teedirig downwardly from the lower ends ot' the ducts in the side :tztces oi the drill body mid shietds attached along" eorrespondihg sides of the grooves and open at the opposite sides and arranged in overlying relation to the grooves.

testimony whereof 1t hove signed my home to this specificotioe. 

